Mechanism for high geographical change but not killing everything

Question

Premise: Earth has a magical cataclysm that pulls up new mountains, pushes down parts of landmasses, and generally reshapes Europe enough to make it unrecognizable (to the average person looking at a world map) in a period of weeks.

Problem: I'm trying to stick to more 'rational' magic that obeys most laws of physics (and with zero unexplained handwavium), and all the ways I can think of to do that much geographical change would probably end up kicking up so much dust and debris that it'd choke out the sun, killing plant life, and then everything that depends on plants.

Limitations: I want as few laws of physics broken as possible in the causal action, but for the result to be able to be explained entirely by physics. This means something like a magical push on tectonic plate ignoring strength/inertia/mass issues but with a result of making plates crash together and pucker into mountains like they would naturally do in response to that stimulus.

Goal: Make the geography/shape of Europe unrecognizable on a world map in a matter of 30 days, and have at least some of European humanity survive (while still living in Europe).

Can you think of any plausible, semi-rational ways to achieve this end?

Answer 1

By wanting as FEW laws of physics broken as possible, I am presuming you are allowing SOME laws of physics to be broken.

If this is the case, then I suggest that very localized reversals of the gravitational constant would do it.

In various areas of the Earth's crust, if gravity completely reversed, and the sections of mantle started pushing instead of pulling, the contours of Europe would certainly change. Since all of the energy was provided by gravity, or the reversal of gravity, and this 'gravitational energy source' has not really ever been qualified, quantified, or accounted for, you would be on safe ground 'conservation of energy' wise.

I mean, consider that it is posited that black holes squeeze matter into infinitesimally small areas, and cause tremendous amounts of matter to be accelerated, without really explaining where the energy is coming from to do this, except that no 'energy balance' is imbalanced, except some vague 'gravitational energy' that seems to have no source, except the 'distortion of space/time into a well', except that no energy is expended in doing so, except that the 'conservation of energy' seems somehow not unbalanced, except that maybe it has something to do with 'dark energy', except that maybe there is some form of energy we really don't know about,... Lot's of 'excepts', which sounds a lot like handwavium in itself. What if that 'well' just turns into a 'mountain', by simply inverting 'gravity'? Same 'energy source', only in reverse application. Wherever the source of 'energy' or 'method' to 'draw things together', it is the same source of energy or method that 'pushes things apart'.

Make the phenomena local, and very deep in the earth, so that material on the surface is still bound to the earth, and does not get projected into space. Water would still seek the lowest point.

Earthquakes do not produce dust clouds

You could still posit earthquakes on a mass scale, caused by the gravitational reversals. I do not recall any widespread dispersal of dust clouds in the air during earthquakes (certainly not to the extent of volcanic activity), so you seem to be safe in that regard. Earthquakes, no matter how extreme, are not noted for obscuring local vision, let alone the sun. Although intense, the energy is distributed over a very wide area, insufficient to give any one particle enough to overcome gravity.

Answer 2

The simplest way to do something like this semi-realistically and without the knock-on effects being too catastrophic is to dramatically raise sea levels. Unfortunately even melting all of the ice on Earth won't raise it enough to make Europe unrecognizable on a world map, so you will need some magical means of adding more water (i.e. portal to a water world) or displacing a huge amount of ocean (forcefield appears in middle of pacific and expands until it's displacing most of the water or something.) Maybe even changing the rotation of the earth's axis (very gently, over the course of the month) so that the equatorial bulge of the oceans is now over Europe. However you do it, get the sea level up about 200m from where they are now and Europe starts looking quite dramatically different. Obviously the effects will be catastrophic in the lower elevation areas, but the high ground should be relatively unscathed so humanity surviving shouldn't be a problem.

Answer 3

You can switch a lot of the electrons on the continent into protons.

Based off this xkcd What if answer, changing lots of particles to the same polarity will cause them to repel and try to move apart. This change can be done with magic or simply explained by some freak particle collider accident shooting protons or electrons into the surrounding rock for more than 2,000 miles. Keep in mind that the density of the particles can be very spread out, because they will interact with the atoms already present in the bedrock.

When these particles become trapped in the rock, they will naturally repel some particles already there. If there are enough of the particles, they will shift the rock by a substantial amount. All together, this will move the bedrock of Europe, changing its shape and physical features. Also keep in mind that the density of the particles does not need to be remotely as high as in the xkcd answer, because we are not trying to create a black hole.

Unless you have a reason to choose one over the other, my suggestion would be to use protons for this purpose, not electrons. The protons have a non-negligible mass, and they won't move around as much as the electrons might. The use of a ground wire illustrates this: electricity can be conducted into the ground, and the electrons just go though the rock into wherever it is that they go. A proton will tend to stay in one place because it can't move as easily.

Forewarning:

I have had the problem of unfair criticism on another one of my other recent answers involving magic. As I said there and I will say here, feel free to critique the scientific part of this answer and give me feedback. Do not, however, critique my use of the magic tag. The magic tag allows a certain, if limited in this case, measure of handwaving allowed. If you have a problem with the magic tag, do not complain on my answer. Either complain to the asker, or complain about the tag itself on meta. I am allowed to use the magic tag because the asker of the question is allowing answers to use it.

Answer 4

If the cataclysm focuses on the center of Europe, and the landmasses surrounding it pull in to fill the gap of what was destroyed, then you should have surviving people, animals, plants, etc in those outer sections. I'm imagining something like the center being sucked down into oblivion and the rest being drawn to close the hole.

If you need it, perhaps the extra mass from the lost center can go down and around the surviving parts then rise up to be landfill (it will surround what is left of Europe). That land will be dead but will fill in with life within a few decades (perhaps not all microbes die, so at least plant life and insects can come back faster, which means humans and livestock can deliberately move there).

Answer 5

Space disappears.

There is an accident at CERN which sends spacetime ripples outwards in all directions. Each wave at its nadir vanishes an area of space: this area and whatever was in it is gone, and areas formerly separated by this space are now adjacent. These areas do not move together or rush in to fill a void - the space between is no longer a space. Each wave at its zenith adds space, which appears in between areas formerly adjacent. You can decide what is in this introduced space - perhaps the stuff from the disappeared spaces? Or maybe weird stuff from somewhere else? If from somewhere else that implies disappeared stuff from earth might have gone there and maybe might come back.

These ripples can change as you see fit, perhaps growing larger as they propagate or changing in mysterious ways. They may be a recurrent phenomenon - the rearrangement might continue to greater or lesser degrees over time.

In any case, rearranging space and what is in it is a way to alter topography without unleashing tremendous energies. Also the continuing presence / threat of the "change wave" lends energy to the story.